1. Field of the Invention
The present invention relates to a gas supplying apparatus that is configured to supply gas to a chamber where a predetermined process is performed at a pressure lower than an atmospheric pressure. The present invention also relates to a cylinder cabinet, a valve box, and a substrate process apparatus that are provided with the gas supplying apparatus.
2. Description of the Related Art
There exist semiconductor fabrication apparatuses that utilize a process gas, such as a chemical deposition apparatus and an etching apparatus. Such semiconductor fabrication apparatuses are connected via a gas supplying pipe to a gas supplying source an example of which is a cylinder cabinet. Here, a pressure within the gas supplying pipe is maintained higher than an atmospheric pressure by 0.1 MPa in many cases. When the pressure within the gas supplying pipe is higher than the atmospheric pressure, there exists a slight possibility that a gas leakage may occur, for example, through joints provided in the gas supplying pipe. In order to address such a gas leakage, the joints may be collectively arranged within a container called, for example, a valve box that is connected to a predetermined evacuation apparatus. The valve box is constantly ventilated or evacuated by the evacuation apparatus, and monitored by a gas leakage detector. When a gas leakage is detected by the gas leakage detector, the valve box is urgently evacuated at a greater evacuation rate by the evacuation apparatus, thereby preventing the gas from leaking into a factory environment.
In addition, because there may be a possibility of gas leakage from a welded part of the gas supplying pipe, plural gas leakage detectors are arranged on a ceiling of the factory along the gas supplying pipe.
In addition, when a liquid source is used, the liquid source needs to be heated in order to increase a vapor pressure above the atmospheric pressure thereby to produce vapor or gas of the liquid source, which may lead to precipitation of the vapor or gas of the liquid source in the gas supplying pipe. When such precipitation occurs, the vapor or gas of the liquid source cannot be supplied at a desired flow rate, or the gas supplying pipe may be corroded by the precipitated source. Therefore, the gas supplying pipe needs to be heated by using a tape heater in order to avoid precipitation.
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2006-61824
Patent Document 2: Japanese examined patent publication No. H7-50418